1. Field of the invention
The present invention relates to a PC card detachably installed and used for information processing devices, such as a personal computer or a digital-still-camera, to process a variety of information.
2.Description of the Related Art
A PC card is detachably installed and used for information processing devices, such as a personal computer (an abbreviated name "PC" is used hereinafter) or a digital-still-camera, to process a variety of information of characters, voices or images, and also used for an increase in ability of a variety of processes and an expansion in processing function for the information processing devices.
Originally, the PC card has been internationally standardized based on a unified standard (PC Card Standard) published by the PCMCIA (the Personal Computer Memory Card International Association) which is an association established to form a card device standard for the PC, and utilized mainly for a portable compact PC such as a notebook PC or PDA. Physical specification (a visual shape) of the PC card is a card type with a length of 85.6 mm and a width of 54.0 mm and classified in type I, type II and type III depending on the difference of thickness. A two-piece connector with 68 pins is used for a PC card connector. The PC card is used by inserting the connector in a PC card slot of a PC card interface provided in the portable PC and the like and can be pulled up from the PC card slot when it is not used.
Thus, since the PC card is easily detachable and superior in portability due to its compact size, the application has been spreading not only to a semiconductor memory card as an auxiliary storage, but also to the auxiliary storage having a hard disk device such as a magnetic disk, and to the related field of communication and network such as a modem function or a LAN function (Local Area Network). Further, the field of application for the use of the PC card has been spreading without being limited to the portable compact PC. For example, by being used for a digital image information processing device such as a digital-still-camera, the PC card is used as a image storage detachable and superior in portability or as a data transfer device (for example: a LAN card or a Modem card) to transfer the memorized images in the camera to the PC and the like.
Conventionally, it has been required to install an extension board with a predetermined function in an extension bus slot or to install an internal substrate module connecting to the mother board of the PC to provide a desired processing ability or processing function to the information processing device, so involving difficulties in exchange and portability of the substrate. However, with the PC card, the desired processing ability and function are instantly provided by exchanging the PC card to insert in the slot, therefore providing an advantage of easiness in handling. It should be noted that there are several methods such as pulling and inserting or placing to cramp for attaching/detaching the PC card to/from the information processing device.
Recently, along with the development of high integration technology of semiconductor devices, the development of the information processing devices including a more compact PC, digital-still-camera, digital video camera, or commercial equipment such as portable audio equipment results in a demand for the emergence of the more compact PC card, in addition to the emergence for the conventional PC card based on the PCMCIA standard intended for the use of the portable PC. Therefore, the following standards for the compact memory card are proposed and actually appear in the market as products.
The first standard is the "Compact Flash (the registered trademark of SanDisk Corporation)" proposed by the CFA (Compact Flash Association). It is a compact flash memory card with approximately 8 MB in capacity having an outside dimension of 36.4.times.42.8.times.3.3 mm.sup.3. The second standard is the "Small PC Card" proposed by Matsushita Battery Industrial Co., Ltd., the JEIDA (the Japan Electronic Industry Development Association) and the PCMCIA, having an outside dimension of 45.0.times.42.8.times.5.0 mm.sup.3 with approximately a half-length of the conventional PC card. The third standard is the "Miniature Card" proposed by the Miniature Card Implementers Forum and the PCMCIA, with an outer dimension of 38.times.33.times.3.5 mm.sup.3.
The fourth standard is the "SmartMedia (the registered trademark of Toshiba Corporation)" by the SSFDC Forum. This is a flash EEPROM card with a capacity of approximately 2.about.16 MB having an outside dimension of 37.times.45.times.0.67 mm.sup.3. The fifth standard is the "MMC (MultiMedia card)" proposed by the MultiMedia Card Association. This is a flash EEPROM card with, for example, approximately 10 MB in capacity having an outside dimension of 24.times.32.times.1.4 mm.sup.3. A sixth standard is the "Memory Stick (the trademark of Sony Corporation)" proposed by Sony Corporation. This is an EEPROM with, for example, a capacity of approximately 8 MB having an outside dimension of 21.5.times.50.times.2.8 mm.sup.3. Moreover, a compact PC card with a hard disk drive using magnetic storage is also developed. In this application, each of the compact cards having the aforementioned functions including the similar cards is generally named a PC card.
The object of the PC card is to solve the problems regarding the insufficiency of compatibility among the IC cards as well as the limitation of the extension of the use and the function, which have been in the past owned by the IC card used mainly for the purpose of exchange of a card having magnetic stripes, and further the PC card is realized by newly forming physical specification, electric specification and software specification to extend the processing ability and processing function of the PC and the like. In short, though the PC card has its origin in an IC memory card, it is significantly different from the IC memory card in mechanism and application. Furthermore, it can be referred as an extended function card standardized and realized by electric specification and software specification which are strongly influenced by a PC extension bus architecture. Thus, the application field and technical field are new industrial utility and technical fields which can provide functions far beyond the range of the market intended originally in the IC card.